The present invention relates to the field of cellular communication systems. More specifically, the present invention relates to modeling radio communications networks for use in cellular network planning tools.
As cellular communication has become more popular, cellular service providers have felt increasingly pressured to use the cellular radiofrequency (RF) spectrum as efficiently as possible. Greater efficiency allows a service provider to carry more calls using a given amount of RF spectrum. The problem of efficiently assigning the given amount of RF spectrum, i.e., channels, within a cellular network is a complex one.
Typically, a service provider is allocated a pool of channels for use within a network. The provider controls the assignment of the channels of the pool to various cells in the network. Automated approaches to network planning are being developed to assist service providers in devising channel assignment plans for cellular networks. Some automated network planning tools involve simulating the actual radio communications network to predict the propagation of radiofrequency (RF) signals in order to define the radio coverage areas for base stations, to characterize potential interference within a simulated environment in order to effectively perform frequency planning, to perform hand-off analysis, and so forth.
Typically, a radio communications network includes a plurality of cell sites operated by the service provider. Cell sites are transmit/receive locations through which radio links are established between a switching office and wireless units. The area served by a cell site is referred to as a xe2x80x9ccellxe2x80x9d. The physical components, or constituents, of a typical cell site include antennas, transmit/receive units, and radio controllers. Although cell sites include many similar constituents, their configuration can vary widely from cell site to cell site within a radio communication network depending upon the desired cellular service for a particular cell.
For example, one cell site configuration produces a cell that is sectored into several smaller patterns of coverage, i.e., sectors. Sectoring is applied when the capacity of the cell site is insufficient or when interference becomes a problem. Sectoring divides the number of channels assigned to the cell into smaller groups of channels, which are assigned to a sector through the use of directional antennas.
Another cell site configuration allows a radio signal to be broadcast simultaneously on two different antennas, i.e., simulcast. Simulcast is accomplished by splitting a radiofrequency signal. The resulting split signal is broadcast from two antennas at half the transmission power. Simulcast signal broadcasting allows more flexibility with respect to antenna patterns.
Other cell site configurations include the use of multiple antennas operating at different frequencies, repeaters for amplifying and relaying signals between a serving cell site and wireless units located in a xe2x80x9cholexe2x80x9d or xe2x80x9cweak spotxe2x80x9d in the cell served by the serving cell site, multiple combiners at a cell site, underlay/overlay transmission configurations, and so forth.
In addition to the variety of cell site configurations possible in a radio communications network, other information that affects frequency planning includes the type of service available in the network, communication channels available for assignment, channel assignment constraints, carrier-to-interference ratio constraints, neighbors lists, and so forth. This information coupled with the cell site configurations can be organized in very complex ways to reflect the interrelationships between the various physical components of the wireless system.
In order to accurately model a radio communications network, a network planning tool should desirably be able to readily model the many known and evolving cell site configurations. In addition, the network planning tool should readily associate the cell site configurations with the other related information discussed above for effective frequency planning.
Accordingly, it is an advantage of the present invention that a method and system for modeling a radio communications network are provided.
Another advantage of the present invention is that the method and system readily create a hierarchical data structure that models the radio communications network.
Another advantage of the present invention is that the method and system allow the hierarchical data structure to be modified in a cost effective manner.
Another advantage of the present invention is that the method and system associate related frequency planning information with the radio communications network for effective frequency planning.
Yet another advantage of the present invention is that the method and system implement an object oriented programming environment which decreases development time and lowers overall development costs.
The above and other advantages of the present invention are carried out in one form by a computer-readable storage medium containing executable code for instructing a computer to create a hierarchical data structure modeling a radio communications network having a plurality of cell sites. The executable code instructs the computer to receive a network configuration for the radio communications network and identify, in response to the network configuration, cell site constituents of one of the cell sites in the radio communications network. The executable code further instructs the computer to create distinct objects to represent each of the cell site constituents and link each of the distinct objects according to a cell site configuration of the one cell site.
The above and other advantages of the present invention are carried out in another form by a computer-based method for creating a hierarchical data structure modeling a radio communications network having a plurality of cell sites. The method calls for receiving a network configuration for the radio communications network, identifying, in response to the network configuration, cell site constituents of one of the cell sites, and creating distinct objects to represent each of the cell site constituents. Communication technology types employed in the radio communications network are defined and technology objects are formed, one each of the technology objects representing one each of the communication technology types. A channel table for the radio communications network is obtained, the channel table encompassing communication channels available for assignment in the radio communications network, and a channel table object is generated to represent the channel table. The distinct objects are linked according to a cell site configuration of the one cell site and the technology objects and the channel table object are associated with the distinct objects.
The above and other advantages of the present invention are carried out in another form by a computing system for configuring a hierarchical data structure modeling a radio communications network. The computing system includes a processor, a computer-readable storage medium, and executable code recorded on the computer-readable storage medium for instructing the processor to create the hierarchical data structure. The executable code includes a cell site constituent identification module for identifying cell site constituents of a cell site in the radio communications network and a distinct object module having cell site classes, each of the cell site classes containing instructions for creating a distinct object representing one of the cell site constituents. The code further includes a communication technology type definition module for defining communication technology types employed in the radio communication network and a technology object module having technology type classes, each of the technology type classes containing instructions for creating technology objects representing the communication technology types. The code also includes a channel table acquisition module for obtaining communication channels available for assignment in the radio communications network and a channel table object module having a channel table class containing instructions for generating a channel table object to represent the available communication channels and a channel class containing instructions for generating logical channel objects for each of a plurality of logical communication channels. An object linking module has instructions for linking the distinct objects in accordance with a cell site configuration of the cell site and an object association module associates the technology objects, the channel table object, and the logical channel objects with the distinct objects.